Not long after returning from a three-day Oxfam relief mission trip to Senegal last week, the 49ers‘ new wide receiver reached out to his new quarterback, Colin Kaepernick.

“I got in touch with him just to see what he was doing,” Boldin said Tuesday. “Just see what he was up to. Try to figure out when we can get together and start working on our chemistry.”

Boldin, 32, knows from recent experience how that chemistry can take time to establish. He was traded to the Ravens in 2010 and slowly began to develop a rapport with Joe Flacco. In 2012, he had 65 catches for 921 yards, the highest totals of his three seasons in Baltimore. In four playoff games, he added 22 receptions and 380 yards.

After he joined the Ravens, he spent time working with Flacco after organized team activities concluded. He hopes to have a similar arrangement with Kaepernick, whom he termed a “special kid.”

“There has to be trust factor there,” Boldin said. “I think the thing you saw with me and Flacco last year – like I say, it didn’t just happen overnight. It took, probably, a year for us to get on the same page and for him to have complete trust in me. So, hopefully, me and Colin can get together and kind of shorten that window.”

Boldin arrived in the Bay Area on Tuesday and took his physical, making last week’s trade from the Ravens for a sixth-round draft pick official. The deal was prompted when Boldin refused to take a pay cut from his $6 million salary in 2013. With one year remaining on his contract, Boldin said he’d welcome talk of an extension with the 49ers.